Storage battery.



T. A. WILLARD.

- STORAGE BATTERY. I .APPLICATION H LED Aue.9.'1915.

1,166,102; i Patented Dec. 28, 1915.

UNITED STATES PATENT OFFICE.

THEODORE A. WILLARD, OF CLEVELAND, OHIO, ASSIGNOR TO THE WILLARD STORAGE BATTERY COMPANY, OF CLEVELAND, OHIO, A CORPORATION OF OHIO.

STORAGE BATTERY.

Application led August 9, 1915.

To all whom t may Concern Be it known that I, THEODORE A. lVlL- Lann, a citizen of the United States, residing at Cleveland, in the county of Cuyahoga and State of Ohio, have invented a certain new and useful Improvement in Storage Batteries, of which the following is a full, clear, and exact description.

This invention relates to storage batteries, and particularly to the construction of the vent plug.

One of the objects of the present invention is to form the plug in such a manner that a very much larger filling opening may be employed than heretofore, and so that the plug which is adapted to be screwed into the filling opening will not limit the width of the battery. nor interfere in any way with the connectors on opposite sides of the plug.

A further object is to avoid the liability of imperfect seating of the plug and sealing thereof by means of a gasket, and to avoid liability of leakage of acid due to defective sealing.

A still further object is to eliminate the escape of' acid in the form of spray or small bubbles, which with the batteries in use at the present time pass out through the vent opening provided in the vent plug, and carry acid to the exterior of the cover.

My invention may be briefly summarized as consisting in certain novel details of construction and combinations and arrangements of parts which will be described in the specification and set forth in the appended claims.

In the accompanying sheet of drawings, Figure 1 is a view partly in side elevation and partly in section showing the battery cover provided with my improvements in the vent plug and filling opening; Fig. 2 is a topplan view of the cover illustrating particularly the size of the filling opening which may be employed relative to the width. of the battery; Fig. 3 is a diagrammatic view illustrating particularly the manner in which the spray is prevented from passing through the minute vent opening in the diaphragm of the vent plug and the manner in which pressure may be relieved in the event the battery is charged so rapidly that excessive gas pressure is created.

Referring now to the drawings, 10 represents the battery cover which is provided Specification of Letters Patent.

Patented Dec. 28, 1915.

serial No. 44,376.

midway between. the openings 11 for the terminal posts and connectors with a vent plug opening 12 which is threaded on the interior and receives the threaded part of a vent plug 13. In ordinary constructions the vent plug is provided above the threaded part with a laterally and outwardly projccting flange which bears down firmly upon a gasket in turn resting on the cover and provided for the purpose of sealing the joint between the cover and the vent plug, so as to prevent leakage of gas or acid between the plug and the cover. In accordance with one feature of the present invention, I omit this flange and make the upper part of the plug, that is, the part which is above the threaded part and projects above the cover of no greater diameter than the threaded part itself, and instead of sealing the plug in the threaded opening by a gasket at the top of the cover I provide at the base. of the vent plug opening 12 an inturned flange 14, and between this flange andthe lower end of the plug I provide a gasket 15 which when the plug is screwed in position seals the opening against leakage of acid or gas between the plug and the threaded wall of the plug opening. Preferably the base of the plug is provided with two or more openings 16 for the escape of gas to the interior of the plug and for the return of acid which is carried up through the base of the plug to the diaphragm, which will be referred to presently. lVith this construction the vent plug opening or filling opening may be made of maximum diameter or width, the eXtreme edges of the opening coming very close to the side edges of the battery, as illustrated in Figl. This is of great advantage in filling or refilling the battery.

A further advantage derived from omitting the laterally projecting flange at the ltop of the threaded part of the plug or of making the upper part of the plug of no greater diameter than the lower part, lies in the fact that the plug does not interfere with the terminal posts or connectors which are fitted onto the posts and permits the connectors to be brought close to the filling opening.

A further feature of my invention resides in a diaphragm 17 which is provided in the upper portion of the lug. Witnconstructions provided heretofore the vent opening of the diaphragm had to be made sufficiently large to provide for the escape of gas substantially as rapidly as it was generated in the battery, regardless of how rapidly the battery was being charged. To accompllsh that result the vent opening provided in the diaphragm had to be made of such size that gas in the form of spray or in the form of small globules or bubbles would pass out through the vent opening, and acid would be deposited on the exterior of the cover. In accordance with this feature of my invention, I provide a diaphragm with a very minute vent opening 18 too small, in fact, for acid in the form of spray to escape therethrough, and to avoid serious effects resulting from the building up of gas pressure on the interior of the battery in the event the gas is generated too fast toescape through the minute vent opening, I form the, diaphragm of soft rubber and hold "it in the plug in such a manner that under excessive pressure the diaphragm may be lifted from the plug, the plug being provided above the diaphragm with no obstruction which will,

prevent the forcing of the diaphragm from the plug under predetermined excessive pressure. The diaphragm may be held in the upper part of the plug simply by friction, but in this case the edge of the diaphragm is forced into a slightly undercut part of the'plug. The advantage of this form ofy diaphragm and with the minute vent opening, is illustrated in Fig. 3 wherein it will be seen that the vent opening is too small to permit the escape of bubbles or spray, the globules of which are shown 'at 19. The eifect of this is that the bubbles which consist of gas surrounded by a lm of liquid will strike the diaphragm and will then drop down into the battery, while liberated gas or the gas freed from the acid passesl out through the small vent opening. In this same figure I have shown by dotted lines the manner in which the gasket can be forced out of the plug ifthe gas is generated too rapidly to escape through the minute vent opening.

Having thus described my invention, what I claim is 1. In a storage battery, a battery cover having an opening for a vent plug and having an inwardly extending portion adjacent the base of the opening forming a shoulder,

a vent plug fitted tightly into said opening and a gasket between the lower end of the plug and the shoulder, said gasket sealing the battery against leakage between the plug andthe opening.

2. In a storage battery, a batteryA cover having a threaded opening for a vent plug and an inturned flange at the bas/e of the opening, agasket between the lower end of the plug and said flange and sealing the plug against leakage between the plug and `the threaded opening, said plug having a portion projecting upwardly beyond the opening and of no greater external diameter than the threaded portion.

3. In a storage battery, av cover provided with a vent plug having on the interior thereof a diaphragm held in the plug-in such a manner that it may be lifted from the plug by gas pressure in the battery, said diaphragm having a minute vent opening.

4. In a storage battery, a cover having a vent plug, and a diaphragm located in and extending across the plug, said diaphragm being formed from soft rubber and being provided with a minute vent opening.

5. In a storage battery, a cover having a vent plug, said vent plug being the shape of a cup with an open top and with a base having one or morepoutlet openings for gas, a diaphragm in the plug and extending transversely thereof, said diaphragm being held frictionally in the plug and having a small vent opening.

In testimony whereof I hereunto aiix my signature.

THEODORE A. WILLARD. 

